Hmmn... still seems to come down to 'whatever twiddles your biscuit'!
I'm constantly torn between using 'psionics and magic' and 'magic' exclusively, in part a product of the assumptions of the system itself (e.g. you do not need 'psionic power points' but you
do need 'magic power points'). For me, though, the overall feel just cries out for the blanket application of magic (despite the odd draw back to using both!
)... not only do you have the utilisation of 'warp energy' (mana), but the collateral affects of using psionics described in the 'fluff' (cf.
Eisenhorn and 'psionic ice', or the
Ragnar books and the pyrotechnics assocated with the psychometric seance held by that Inquisitor woman). It also takes a more compartementalised approach with psionics such that they are more akin to powers, such as those presented in
Trinity, that are discrete rather than a continuum created by a psionics system (again, the one that I'm using)...
Psykers therefore become 'psionic-aspected magicians'. For the most part they utilise 'spells' that could be represented as psionics, but essentially operate as spells. Ritualisation which is endemic throughout the 40k universe might also go to further substantiate this given that psionics is more often than not represented as more 'intuitive' than learned. Also, in 40k 'powers' can in essence be learned, hinting at a more integrated approach than the categorised 'psionic powers'...
Magic seems to fit more of the holes than psionics...
Personally speaking I'm fiddling around with the working premise that each psyker has a 'native level' of energy with which to practice their abilities (a byproduct of the strength of their connection to the warp). Channelling this level of energy is unlikely to draw attention to the individual since it is 'naturally filtered' through the 'soul'. However, channelling higher levels of energy automatically strengthens the connection between the warp and the matterium and, therefore, the potential dangers. Keep on channelling and not only does the bridge get stronger, but you're also putting out a 'beacon', or dipping a bloody toe, then bloody leg and finally bloody body in a pool full of sharks. (This is based off the modified concept of Threshold and Calamity in S. John Ross'
Unlimited Mana system for
GURPS.) The more you channel the brighter the beacon and the longer it's on...
Added to this is the concept of 'native ability', the sheer fact that different psykers have different facilities with their various powers (this is the level of Magical Aptitude, equating roughly to alpha, beta, gamma, etc., psykers; primary and secondary psykers are something else entirely). Each 'power' is, of course, a spell with a varying cost in terms of energy...
(And, of course, eldar have a pathological (and sensible!) aversion to channelling warp energy directly beyond their 'native ability' (threshold), hence the utilisation of the Seer Runes as 'power sources' or 'power pools'.)
So how does this rough model fit in with the 'fluff' that you posted? It all comes down to 'male genitals'. No, I'm not saying that it's a pile of <insert your own appropriate rude word>, but rather the traditional issue of size: is it the size that matters or what you do with it? Of course, grossly its what you do with it but as everyone knows that's not everything: size does have an impact. Thus with how I view psykers. It's not a question of the size of your ability, but how you use what you've got...
"Low Level" Generally speaking the psyker will not channel energy past their threshold and, as such, their only 'draw' upon the warp is in the gradual recharge moderated through their 'soul'. They maintain the ability to channel energy beyond their threshold, but this increases the calamitous effects.
Depending on the origin of the psyker abilities may be curtailed by philosopy and tradition. Imperium psykers from the
scholastica psykana will tend to only have 'powers' focussed around (in
GURPS terms) Communication, Mind Control, perhaps a little bit of Necromany and some limited Protection and Warning. They will have an aversion to channelling beyond their threshold due to the 'dangers of the warp'.
Thus, in this matter, one might consider almost any non-radical Imperium psyker to be 'low level'. (And again eldar are pathologically 'low level', but utilise Seer Runes to by-pass the restriction of threshold channelling.)
"Medium Level"Again, the discrete categorisation doesn't quite work here... However, medium level practise is more than likely when an individual begins to channel energy beyond their threshold: they are truly dabbling with 'warp energy'. This introduces Calamity (mal-effects of channelling warp energy), as well as the potential for attracting a daemon who can attempt position given the strong bond between the matterium and immaterium.
Radicals and the generally pragmatic might be thought of as touching upon the 'medium level'.
Of course, Astropaths can be of any level. It's not how 'big' or powerfully they practise their discipline, merely the fact that they are inherently more open to daemonic influence. In other words, they are secondary psykers. I find the idea that primary psykers are strong enough to resist the 'daemonic influence' to be tenuous, preferring the Draco model of them being able to 'hide their psyker light'.
"High Level"Sorcery. No boundaries between "psionics aspecting" of abillities.
Hmmn... so what does that ramble come down to. It's a question of what you do, what you think and what you're told rather than an inherent 'power level'. Kind of. Erm.
Oh and thanks, Phillip. I really enjoyed this... nice to air out ones thought on a subject they enjoy. As a roleplayer whose main interest is in the roleplaying potential of the universe (beyond the interest in the project for the project's sake), it's always nice to return home and not to have to think about wargaming!